Ruminants, Volume 4, Issue 3 (September 2024) – 3 articles

The objective of this study was to evaluate the effects of breed, lactation number, and lameness on lying time, milk yield, milk urea nitrogen concentration (MUN), progesterone concentration (P₄), and the calving-to-conception interval (CCI) of lactating dairy cows in Central Texas. A total of 84 lactating dairy cows (Holsteins, Jerseys, and crossbreeds) from a commercial dairy farm in Central Texas were randomly selected and enrolled in this study from October 2023 to February 2024. Cows (60 ± 7 DIM) were enrolled in cohorts weekly for five weeks and were randomly fitted with an IceQube pedometer (IceRobotics, Edinburgh, UK) to track lying time. Lameness and body condition scores (BCS) were recorded, and blood samples were collected once a week. Parameters of reproductive performance included insemination rate, conception rate, pregnancy rate, and the CCI. Monthly dairy herd improvement association (DHIA) testing included milk yield and MUN concentrations. Breed and lactation number had a significant effect on milk yield, MUN concentration, lying time, BCS, and lameness (p < 0.001). Lactation number had a significant effect on P₄ concentrations (p < 0.001). There was a positive correlation between lameness and milk yield (p = 0.014) and a negative correlation between lameness and MUN concentrations (p = 0.038). Full article

(1) Background: Multiple point-of-care (POC) glucometers are in use in veterinary medicine, but few are compared to each other. This leaves the potential for clinicians to be unaware of the effect of bias when comparing results from different POC glucometers. (2) Methods: Samples from healthy calves and ewes were simultaneously compared with two POC veterinary glucometers, the Precision Xtra and the AlphaTrak2, under both the “canine” and “feline” settings. The results of each sample were statistically analyzed with linear regression and Bland–Altman analysis. (3) Results: 170 samples from healthy calves and 108 samples from healthy ewes were available for comparison. Calves: The AT2 consistently overestimated blood glucose concentrations when compared to the PX device with the calves. Correlationt with the PX was r = 0.8496 (canine setting) and r = 0.8861 (feline setting). Both the canine and feline settings demonstrated a consistent bias (41.11 and 33.64 mg/dL, respectively). Ewes: The AT2 consistently overestimated blood glucose concentrations when compared to the PX device with the ewes. Correlation with the PX was R = 0.4710 (canine setting) and R = 0.7269 (feline setting). Both the canine and feline settings demonstrated a consistent bias (21.23 and 14.54 mg/dL, respectively). (4) Clinicians should be aware of the potential for consistent bias when evaluating calf and sheep blood glucose concentrations as the AT2 device, at both settings, overestimated blood glucose compared to the previously validated PX. This reliability appears to change when the values are farther from the normal ranges, which should be considered when making clinical decisions based on data from these devices. Full article

Bulk tank milk microbiota (BTMM) is affected by various factors, including the characteristics of raw milk, microflora on teat surfaces, and the milking system. Clarifying the influence of these factors is important for producing high-quality dairy products. This longitudinal study describes the annual changes in BTMM at six dairy farms in northern Kanagawa Prefecture, Japan. Bulk tank milk samples were collected six times a year (in February, April, June, August, October, and December of 2022) to give a total of thirty-six samples. After bulk tank somatic cell counts (BTSCC) had been determined, we performed 16S rRNA gene amplicon sequence analysis to clarify the composition of the BTMM. Although no annual changes were observed in the BTSCC and alpha-diversity index, a significant difference in the beta-diversity index was observed between February and August (p = 0.0315). In February, the proportions of the psychrophilic genera Listeria and Enterococcus were significantly increased (p < 0.05). Similarly, in August, the proportion of commensal milk microbiota in the genera Catenibacterium and Acetobacter were significantly increased (p < 0.05). The results of this study suggest that the composition of BTMM in this region changed throughout the year, which may have been influenced by psychrophilic bacteria in winter. Full article